[Sbcl-help] Signature of SB-EXT:MAP-DIRECTORY

[Josef W. <jw...@ra...>]

Hello everybody,

while browsing through http://www.sbcl.org/all-news.html, I found the new
SB-EXT:MAP-DIRECTORY function, which would come very handy in a project I am
planning to port from perl to CL.

I think this new feature could be improved considerably by a little change of
its lambda-list:

  (defun map-directory (directory &key (directory-function nil)
                                       (file-function nil)
                                       (symlink-function nil)
                                       (errorp t)))

If no symlink-function is given, behaves like :classify-symlinks t

If defined this way, the invocation in DELETE-DIRECTORY could be reduced to:

  (map-directory dir :directory-function (recurse-merged dir)
                     :file-function      (delete-merged dir)
                     :symlink-function   (delete-merged dir))

With this change, MAP-DIRECTORY would be called only once, eliminating
opportunities for race conditions. (at least theoretically)

One more improvement would be if MAP-DIRECTORY would pass to the callee
what kind of file (dir, file, whatever) the current entry is. For
symlinks, this would be the kind of the link-target.

Any opinions?

PS: Making traversals _safe_ is a totally different topic, of course.

-- 
Josef Wolf
jw...@ra...